EXPLANATION OF THE FIGURES. 



PLATE VII. 



Fig. I. Twig of Acer casium from the terminal bud of which four leaves have 

 developed. At (a) (a) the bases of the petioles of 3 leaves which have 

 been cut off are shown. (6), scars marking the position of the bud- 

 scales which have just been shed, (c) (c), scars marking the position 

 of the bud-scales which have similarly been shed at the beginning of the 

 annual growth in previous years. The twig thus shows the completed 

 growth of 3 years and is just commencing its 4th year's growth. 

 2. Twig of Carpinus viminea which has just commenced its annual growth. 

 (a) to (), part of the winter twig ; (^) to (c), part of the spring shoot 

 which has just developed from the terminal bud of the winter twig. At 

 (3), the lowest brown bud-scales have fallen off, but the pair of scaly 

 stipules at (</), which flank the petiole of the lowest leaf, were actually 

 present as bud-scales in the winter-bud, and at their tips the dark brown 

 portions which were exposed on the outside of the winter-bud are still 

 visible At (e) (*), the stipules are larger, but in them also the dark 

 portions which were exposed in the winter-bud are still visible. At (c), 

 the stipules are normal and no dark portions are visible. In this case 

 the bud-scales are obviously modified stipules. 



